I am working on a speech about social media and its pros and cons. I am having some trouble on how to start it with an introduction and need help.

The introduction of a speech is generally intended to do two things, capture the interest and the goodwill of your audience. 

One way to engage people's interest is to begin with a striking quotation, unusual fact, or interesting anecdote. These types of openings make people curious and make them likely to wish to hear more about your topic.

For anecdotes, you could use an interesting experience of your own or one of your friends. As...

The introduction of a speech is generally intended to do two things, capture the interest and the goodwill of your audience. 

One way to engage people's interest is to begin with a striking quotation, unusual fact, or interesting anecdote. These types of openings make people curious and make them likely to wish to hear more about your topic.

For anecdotes, you could use an interesting experience of your own or one of your friends. As you do your research, you will find many strange facts. For example, according to the Huffington Post, "The fastest growing demographic on Twitter is the 55-64 year age bracket." This could be an interesting way to start a speech as many people associate social media primarily with young people.

Another possibility for an introduction is showing how your paper could be useful to your audience. For example, if one of the "cons" against social media use is the expense of data plans, and you promise to discuss ways to avoid this expense, people will listen because they can benefit directly by paying close attention to what you have to say.